1. Field of the Invention
The present invention relates to a jack, and more particularly to a jack having a safety effect.
2. Description of the Related Art
A conventional jack in accordance with the prior art shown in FIG. 6 comprises a base 80 provided with a plurality of locking teeth 81, a lift arm 82 pivotally mounted on the base 80, and a locking rod 84 having a first end pivotally mounted on the lift arm 82 and a second end locked on the locking teeth 81 of the base 80 to prevent the lift arm 82 from being lowered down too rapidly when the power of the lift arm 82 disappears accidentally. However, the user needs to push the locking rod 84 to engage the respective locking teeth 81 of the base 80 when the lift arm 82 is lifted to a determined position, thereby causing inconvenience to the user when operating the jack, and thereby wasting the manual work. In addition, the locking rod 84 is not engaged with the respective locking teeth 81 of the base 80 exactly, so that the locking rod 84 is easily disengaged from the respective locking teeth 81 of the base 80, thereby causing danger to the user.